Background and aims:Environmental pollutants,particularly organochlorine insecticides like endosulfan(ENDO),are increasingly linked to liver toxicity and related diseases.Despite its widespread historical use,the mechanisms underlying ENDO-induced liver damage remain poorly understood.This study aims to elucidate the cellular and molecular mechanisms of ENDO-induced hepatotoxicity.Methods:C57BL/6 mice were exposed to ENDO for two weeks.Single-cell RNA sequencing(scRNA-seq)was subsequently performed on mouse livers to explore ENDO-induced hepatotoxicity at the single-cell level.Differentially expressed genes(DEGs)across cell types and treatments were identified and then subjected to pathway enrichment to uncover key biological processes affected by ENDO.Transcription factor(TF)regulatory network,pseudotime trajectory,and cellular communication analysis were used to explore the molecular and cellular changes after ENDO exposure.Results:ENDO not only caused direct hepatocyte injury but also activated hepatic stellate cells and lymphocytes,triggering inflammatory responses with upregulation of multiple key chemokines and cytotoxic genes.Additionally,ENDO exposure led to the recruitment and activation of myeloid cells,contributing to the inflammatory milieu.An increase in intercellular communication and changes to the hepatic microenvironment,especially the interaction between activated hepatic stellate cells and CD8+T cells were observed,further implicating these processes in ENDO-induced liver damage.Conclusions:This study provides new insights into the cellular and molecular mechanisms underlying liver injury induced by organochlorine insecticides like ENDO.Key genes and pathways involved in ENDO-associated liver toxicity have been identified at a single-cell resolution.These findings suggest that altered cellular communications and inflammatory responses may play pivotal roles in the pathogenesis of ENDO-induced liver injury.

Sepsis is characterized by a severe and life-threatening host immune response to polymicrobial infection accompanied by organ dysfunction.Studies on the therapeutic effect and mechanism of immunomod-ulatory drugs on the sepsis-induced hyperinflammatory or immunosuppression states of various im-mune cells remain limited.This study aimed to investigate the protective effects and underlying mechanism of artesunate(ART)on the splenic microenvironment of cecal ligation and puncture-induced sepsis model mice using single-cell RNA sequencing(scRNA-seq)and experimental validations.The scRNA-seq analysis revealed that ART inhibited the activation of pro-inflammatory macrophages recruited during sepsis.ART could restore neutrophils'chemotaxis and immune function in the septic spleen.It inhibited the activation of T regulatory cells but promoted the cytotoxic function of natural killer cells during sepsis.ART also promoted the differentiation and activity of splenic B cells in mice with sepsis.These results indicated that ART could alleviate the inflammatory and/or immunosuppressive states of various immune cells involved in sepsis to balance the immune homeostasis within the host.Overall,this study provided a comprehensive investigation of the regulatory effect of ART on the splenic microenvironment in sepsis,thus contributing to the application of ART as adjunctive therapy for the clinical treatment of sepsis.